Baseball Discussion Group

I thought I understood the distinction between a curve ball and a slider, but while watching a game on TV which showed where a pitch was relative to the strike zone, and also its speed and type, I realized there were aspects I did not understand.

I had originally thought a curve ball primarily had a downward break, and a slider primarily a side-to-side break. Is this wrong? Also, does the kind of spin put on the ball by the pitcher determine the type of pitch?

Then there are other breaking pitch variations: knuckle curve, etc. I would also much appreciate any knowledgeable participant's explaining the spin type and break type for these other variations of breaking pitches.

The common curve ball is shown late by advanced pitchers not wanting to tip it to the hitter and it involves more wrist action and the P's back of his hand is facing home plate and for a RHP his fingers are pointed towards first base.

A slider is much tougher on elbows and it involves snapping ones fingers and wrist at a later time than the curve.

Thank you much for your response. I gather from what you described that there is NO systematic differences about the spin and break between a curve ball and a slider. Is this correct?

When I watch a baseball game on TV, a diagram of the strike zone is shown, and each pitch is instantaneously designated as being a curve, a slider, a knuckle curve, a knuckle ball, a 4 seam fastball, a 2 seam fastball, etc. This is along with the specification of the speed. Can you tell me how that pitch type information is determined by whoever or whatever makes that designation?

Hi Buzz - IMHO most of those behind the scenes are guessing at what pitch is thrown except for maybe the major league changeup which can be detected when hitters are way out in front of what may have been perceived as a fastball.

John Smoltz is the best on TV of accurately describing what pitch is thrown.

Curve balls can be from a 12 to 6 (on the clock) or a 1 to 7.

Sliders often spin so tight that the seams blend together and we see or maybe we don't - a Red Dot on the ball. Some sliders come in at at 2 to 8 spin.

Then there are poorly thrown types that are commonly called slurves like what Dennis Eckersley threw or even Sergio Romo.